(Topic ID: 258743)

Creature Lamp Question


By MotoChi

54 days ago



Topic Stats

  • 13 posts
  • 2 Pinsiders participating
  • Latest reply 36 days ago by MotoChi
  • Topic is favorited by 1 Pinsider

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#1 54 days ago

Have a lamp question on my Creature table for a problem I'm having. Curious if anybody has suggestions on where to start looking.

When in lamp test mode, I'm having two different lamps light up on a lamp test. For example, when on lamp 16 (right jet), I'm also having lamp 17 (admit one) light. And when on lamp 17, it also lights lamp 16.

All the lamps that light, from the manual on the lamps table, follow two rows completely. The rows are row 6 (Blue-Red J133-7) and row 8 (Red-Gray J133-9). So, when I am on a test for a lamp in row 6, it lights the lamp in the same column on row 8. And vice versa. For all of them in row 6 & 8. Also happens in game play.

Today, behind the back glass on the driver board, I checked the seating on J133. It's good. I checked the resistors corresponding to Q85 (J133-7) and Q83 (J133-9). They matched the stated resistance.

Tomorrow I will raise the playfield and look for a short. Bit of a headache to raise the playfield for me, as the table is in a basement and don't have clearance in it's location and have to move the table to another area where I just barely get clearance after lowering the feet.

My gut is I have a short in the playfield. I had this problem a couple of years ago, raised the playfield, "touched some wires gently to shift them", problem went away. But now it's back.

This problem is frustrating because I have Pinball Mike D's Raspberry PI Hologram mod installed, and the lamp problem is messing with the awards, so the mod doesn't display awards when it should.

Any ideas or thoughts on how to diagnose? Many thanks.

#2 54 days ago

It sounds like it might be a transistor problem. Here's what the Lamp Matrix entry on PinWiki says

"Ghost" lamps lighting simultaneous with other lamp lighting:

"Ghost" lamp illuminations such as a lamp in column 1 lighting at the same time as a lamp in column 2 on the same row, are almost always due to a shorted lamp matrix transistor providing power (or ground) continuously, and allowing adjacent matrix row or column lamps to light. Note that ghosting here does not refer to LED replacement lamps, which sometime light when they shouldn't in lamp matrix use that was not designed with LEDs in mind.

https://pinwiki.com/wiki/index.php?title=General#The_Lamp_Matrix

#3 54 days ago

Thank you, this is what I was afraid of, and will focus on that. Any idea if the transistor can be replaced, or would the complete driver board need to be replaced?

#4 54 days ago

One other detail on this. I do have some led bulbs in the field, and I believe on one of the rows having the problem. I'm about to start removing them to see if this was the culprit, and not a bad transistor.

#5 53 days ago

removed any new led lights I'd added on either row, problem still exists, so don't think it's the led lights I've added.

#6 53 days ago

Good call pulling those LEDs to see if that was the issue!

Quoted from MotoChi:

Any idea if the transistor can be replaced, or would the complete driver board need to be replaced?

Transistors can absolutely be replaced. It's relatively simple, too, as long as you have a decent soldering station or a solder sucker. But if you've never done board work before, you might want to take the advice of some guy on pinside (who also isn't very experienced) with a grain of salt. Try some of the tips in this thread before taking a board out of the game:

https://pinside.com/pinball/forum/topic/tech-ijw-lamp-matrix-problem

The steps can also be seen here with some animated pics:
https://pinwiki.com/wiki/index.php?title=Williams_WPC#Controlled_Lamp_Operational_Description

What this process will do is determine if you have a board problem or a playfield problem, since this could also be caused by a bad/smashed diode or a shorted wire. If the issue still occurs with the little test lamp, then you know the problem is on the board. If the issue doesn't present itself during this test, you know it originates somewhere in the playfield wiring.

If it does end up being the board, I'm sure there's some experienced techs in the Chicago area that could help you.

#7 53 days ago

Many thanks mskoenen, I'll be back to digging into this more on Sunday. The guides really help. I'm okay at basic soldering, but never on a board before. If I determine it's a transistor prob (or something else needing to be re-soldered), I'll contact a tech.

#8 53 days ago

Yeah, let me know how it turns out. Like I said, I'm not very experienced at this either. I'm just pretty good at finding stuff on the internet. So I'd like to know how you end up fixing this!

I've only done a little board work before, but that was after a fellow pinhead in the area let me practice on some old boards of his that were already dead. And I definitely would have killed any board I worked on first

#9 51 days ago

Dug into the very helpful articles, again thank you. I pressed firmly on the CPU ASIC. It seems seated well. I have pressed firmly on both sides of the ribbon cable, it also seems seated well. Problem still exists.

To isolate the lamps from the board, I removed connectors J133, J137, and J138. I then turned on the machine, set it to single lamp test mode, lamp 11 (P in PAID, Row 1, J133-1, Column 1, J137-1; this was a NON problematic lamp). I connected a test light (no diode or lamp from table, traditional electrical test light) with alligator clip to J137-1 (the column 1 for lamp 11), and touched prob to J133-1 (the row 1 for lamp 11). Test lamp lit (pulse lighting). Probing other pins on J133 and J137/8, all good (test light did NOT light), testing continuity on transistors Q83-90 (TIP-102) only showed continuity (pulsing) on correct transistor Q90, testing continuity transistors Q91-98 (TIP 107) had continuity on all (solid). This seems strange to me that they all had continuity, but maybe that's expected.

I then changed single lamp test to a problematic lamp, lamp 16 (right jet, Row 6, J133-7, Column 1, J137-1). I connected a test light with alligator clip to J137-1 (the column 1 for lamp 16), and touched prob to J133-7 (the row 6 for lamp 16). Test lamp lit (pulse lighting). But also touching J133-9 (lamp 18, admit one, Row 8, 133-9, Column 1, 137-1), also lit up (pulse lighting). Not other pins on J133 lit up. This mimics what I'm seeing on the play field lamps. So I would thing with connectors J133, J137, and J138 disconnected, and seeing the problems right at the pins, rules out and shorts in the play field, or a lamp diode pressing against metal. Correct?

With the machine on, still in single lamp mode test with lamp 16 under test, I began to test the transistors by putting my DMM in continuity mode, touching the 18V lamp matrix test point (TP8), and touching row 6 transistor Q85. Had continuity (pulsing). But I also probed row 8 transistor Q83, and also had continuity (pulsing). Did NOT have continuity on any of the other Q transistors related to the rows (Q84, Q86-90). So this appears to also mimic what I'm seeing on the play field that both transistors are "firing" when only one should. Again strange to me, when I probed any of the column transistors (Q91-98), they all had continuity (this was still with machine on in single lamp mode test on lamp 16). I would have only expected column Q91 transistor to have continuity, but maybe this is expected. Transistors Q83-Q90 are TIP-102 Transistors, Transistors 91-98 are TIP-107 Transistors

The Williams WPC PinWiki link says for a transistor test: "If the game has an entire column of lamps locked on, there is a good chance that a lamp column transistor has shorted. Testing for this condition is very simple. Set your DMM to continuity. Touch one probe to the 18V lamp matrix test point as pictured at left. Touch the other probe to the tab of each of the TIP-107 transistors. Any that "buzz" are shorted and will need to be replaced."

I'm not having an entire column, I'm having two lamps on same column light, for rows 6 & 8, as I step though each lamp on row 6 & 8. For example, col 1 row 6 & 8 lamps light when each is in test mode. col 2 row 6 & 8 lamps light, etc, etc. I'm not sure if the Williams WPC PinWiki link transistor test meant for machine to be on or off. With it off, no continuity on and of the transistors.

Not quite sure what exactly this is all pointing to, other that ruling out any wire shorts or lamp diode touching a bracket problem, and likely a board problem. Just don't yet understand what this is pointing to in the board.

Additionally, maybe related, maybe not. When I turn on the machine, I'll see led on board behind the back glass light, my DMD comes on quickly, my Raspberry Pi & TV (for the creature mod) power on quickly. But the play field takes a LONG time (~5 mins), and I hear a rapid, steady, soft clicking (2-3 clicks a sec) in the speaker. Then it stops, play field lights come on, and the first start up creature sound plays. This is also very odd to me, has existed before the lamp problem, but hadn't affected play in the past, prior to lamp problem.

Does any of these tests explain anything. Basically, I think I'm seeing two row transistors fire when only one should. But not understanding cause, as transistors seem ok.

#10 51 days ago
Quoted from MotoChi:

So I would thing with connectors J133, J137, and J138 disconnected, and seeing the problems right at the pins, rules out and shorts in the play field, or a lamp diode pressing against metal. Correct?

I believe that is correct.

Quoted from MotoChi:

Again strange to me, when I probed any of the column transistors (Q91-98), they all had continuity (this was still with machine on in single lamp mode test on lamp 16). I would have only expected column Q91 transistor to have continuity, but maybe this is expected. Transistors Q83-Q90 are TIP-102 Transistors, Transistors 91-98 are TIP-107 Transistors

I seem to remember reading somewhere that the tests you do for TIP-102 won't work for TIP-107.... Or vice versa, since I can't remember and now I can't find where I read that.

But I would guess that what you're seeing with Q91-98 is expected. Because you're not seeing an issue centered on columns, but on the rows. That is, only the lamps in row 6 erroneously trigger the corresponding lamp in row 8 (albeit in the same column).

Quoted from MotoChi:

With the machine on, still in single lamp mode test with lamp 16 under test, I began to test the transistors by putting my DMM in continuity mode, touching the 18V lamp matrix test point (TP8), and touching row 6 transistor Q85. Had continuity (pulsing). But I also probed row 8 transistor Q83, and also had continuity (pulsing). Did NOT have continuity on any of the other Q transistors related to the rows (Q84, Q86-90).

If it were me, I would try replacing Q83, since it sounds like it's shorted. But, again, at best that would be an educated guess from me.

A transistor of that size isn't super difficult to remove from a board, if you have one of those little solder vacuum pumps for less than $10, like this:

amazon.com link »

Just take that board off the game, heat up the solder on each of the three legs of that transistor, and suck it up with that pump. After a few rounds of that, you'll be able to gently pull that transistor off the board.

But I totally understand if you'd rather not try any of that based on the guess of a weirdo on Pinside. From what I've been reading, when people are presented with an issue like this the experts say something like, "time to break out the logic probe!". I do own one of these but I have no idea how to use it, since I haven't had the reason to use it yet.

EDIT: I forgot to add that it definitely sounds like you've narrowed the problem down to the board. And if you're uncomfortable with board work, I would suggest finding a tech in the area that can help. Even paying for a tech will be a lot less than buying a whole new board.

#11 51 days ago
Quoted from mskoenen:

If it were me, I would try replacing Q83, since it sounds like it's shorted. But, again, at best that would be an educated guess from me.

The thing is, I'm not yet sure if the problem transistor is Q83 or Q85. When I single test a lamp related to Q83, both the Q83 lamp and the Q85 lamp fires, and both transistors show conductivity. And vice versa, when I single test a lamp related to Q85, both the Q85 lamp and the Q83 lamp fires, and both transistors show conductivity.

Quoted from mskoenen:

But I totally understand if you'd rather not try any of that based on the guess of a weirdo on Pinside.

You are no weirdo! I sincerely appreciate the help. I've got two recommendations now for a tech in Chicago area, will prob contact him, as I'm fearful of soldering on a board, and also very limited time for next month to investigate further. But thank you so much for all the pointers. I'll respond back here with the diagnosis, but might be a few weeks before I can even schedule a tech to take a looksie.

#12 50 days ago
Quoted from MotoChi:

I'll respond back here with the diagnosis, but might be a few weeks before I can even schedule a tech to take a looksie.

Yes, please do! Definitely an issue I haven't seen before, so I'd like to know the answer. Good luck!

2 weeks later
#13 36 days ago

Just a follow up. mskoenen

Had a tech out today to look at the table. First thing he did was to disconnect all the PinballMikeD LCD RasPi mod on the driver board (J-133 area), and reconnect the table as normal. Then retested the lamps, noticed all lamp matrix functioning as intended (likely ruling out a board problem). He then tested some of the wires that run from the back glass to the RasPi unit, and noticed a short in 2 of them. He then reconnected the RasPi connections to the driver board, and reseated the connections to the RasPi unit. Then retested the lamps. Lamp matrix worked as intended. He couldn't offer any explanation other than a bad seating on the RasPi. Shortly before I noticed the problem with the lamps, I had been in at the RasPi dealing with a SD card that got corrupted and needed to be reformatted. The card is in an awkward spot, hard to reach, so maybe I did "bump" something (though I do take rings and watch off when working in open table). Dunno. But glad it is working, and that it wasn't a driver board problem, and not a super expensive repair. And he resoldered a bad lamp switch while he was in there.

Just a note from the tech. He said any time he deals with lamp matrix issues on modded games, he immediately suspects the mod. I guess I should have homed in more on that. Hope others might learn from this.

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